The perfuming of solid detergents is now standard practice in the art. These products are perfumed on the one hand to provide the consumer with a recognizable and "unmistakable" product in conjunction with the structure and color impression; on the other hand, the incorporation of perfumes is intended to ensure that the articles treated with the detergents, more particularly fabrics, are given a long-lasting perfume which is regarded by the consumer as a performance feature of the particular detergent. Normally, those auxiliaries which do not make a direct contribution to the washing or cleaning process are added last to the detergents. This procedure applies in particular to the "aesthetic" components, such as dyes and perfumes. Perfume is mostly incorporated by spraying the solid detergent granules with perfume which is optionally fixed with powder components to the surface of the solid detergent. The disadvantage of this procedure is that the perfumes are not uniformly distributed throughout the detergent and, in addition, can be partly removed during subsequently drying steps. In addition, the perfume impression of the detergents or rather the articles treated with them is often not sufficiently intensive with this method of perfuming and can only be made satisfactory by increasing the amount of perfume used.
The production of detergent granules is widely described in the prior art literature where, besides numerous patent specifications, there are an enormous number of publications concerned with this subject ranging from individual articles in specialist journals to complete works.
Compacted detergents and processes for their production are described, for example, in DE-A-39 26 253 and DE-A-195 19 139 (both Henkel KGaA). These two documents describe the extrusion of water-containing solid mixtures in the presence of added plasticizers and/or lubricants. There is no reference in either document to the use of perfumes. However, since the extrudates produced without perfumes contain water and have to be subsequently dried, any perfuming required can only be carried out by the conventional method of spraying onto the already dried extrudates.
Earlier German patent application 196 38 599.7 (Henkel KGaA) describes a water-free or substantially water-free extrusion process in which subsequent drying steps can be omitted because a substantially water-free premix with a water content of preferably no more than 15% by weight (this water not being present in free form) is extruded. The perfuming of the extrudates obtained is not mentioned in this document either.
In order to solve the problem of the inadequate perfuming of articles treated with detergents, perfume-containing particles, in which the perfume is so to speak "encapsulated", have been described in the prior art. In particular, complexes of cyclodextrins and perfume are described in the prior art as strong perfumes and fragrances for use in detergents, cf. for example EP 602 139, U.S. Pat. No. 5,236,615 and EP 397 245 (all Procter & Gamble). Microencapsulated perfume oils are also used for this purpose, the perfume preferably being activated in a dryer, cf. EP 376 385 (Procter & Gamble).
The solutions proposed in the cited prior art mainly extend to the perfuming of the treated and dried textiles. If it is desired that the product itself or the freshly washed and still damp laundry should also be olfactorily more noticeable, it has to be additionally sprayed with perfume in the conventional way which, besides the production of the perfume particles, involves another process step.